1. Field of Invention
The invention relates to a luminous device and electronic appliances. In particular, the invention relates to a luminous device including organic electroluminescence materials and an electronic device incorporating the luminous device.
2. Description of Related Art
The related art includes a colored luminous device having a structure in which a luminous element that includes a luminous material, such as an organic fluorescent material, is interposed between a pixel electrode (anode) and cathode. In particular, the related art includes an organic electroluminescent (organic EL) device using an organic EL material. The related art luminous device (organic EL device) is briefly described below.
FIG. 12 is a schematic that shows an wiring structure of the related art luminous device. As shown in FIG. 12, a plurality of scanning lines 901, a plurality of signal lines 902 extending in a direction perpendicular to the scanning lines 901, and a plurality of power lines 903 extending in parallel to the signal lines 902 are wired in the related art luminous device. A pixel region A is provided at each cross-point between the scanning line 901 and signal line 902. Each of the signal lines 902 is connected to a data side addressing circuit 904 including a shift register, level shifter, video line and analogue switch, and each of the scanning lines 901 is connected to a scanning side addressing circuit 905 including a shift register and level shifter.
Each pixel region A includes a switching thin film transistor 913 to supply a scanning signal to a gate electrode through the scanning line 901, a retention capacitor Cap to retain an imaging signal supplied from the signal line 902 through the switching thin film transistor 913, a current thin film transistor 914 to supply the imaging signal retained by the retention capacitor Cap to the gate electrode, a pixel electrode 911 into which an addressing current flows from the power line 903 when the electrode is electrically connected to the power line 903 through the current thin film transistor 914, and a luminous layer 910 interposed between the pixel electrode 911 and cathode 912. The cathode 912 is connected to an electric power circuit 931 for the cathode.
The luminous layer 910 includes three kinds of luminous elements of a red luminous layer 910R, green luminous layer 910G and blue luminous layer 910B, and the luminous layers 910R, 910G and 910B are arranged as stripes. The power lines 903R, 903G and 903B connected to the luminous layers 910R, 910G and 910B, respectively, via the respective current thin film transistors 914 are connected to respective luminescent electric power circuits 932. The power line is independently wired for each color since the addressing potential of the luminous layer 910 is different for each color.
In the above construction, an electrical charge corresponding to the imaging signal supplied to the signal line 902 is retained in the retention capacitor Cap, when the switching thin film transistor 913 is turned ON as a result of supplying a scanning signal to the scanning line 901. The current thin film transistor 914 is turned On or OFF depending on the amount of the electrical charge retained in the retention capacitor Cap. Then, an electric current flows into each pixel electrode 911 from the power line 903R, 903G or 903B through the current thin film transistor 914, and an addressing current flows into each cathode 912 through the luminous layer 910. A light corresponding to the amount of the electric current through the luminous layer 910 is emitted from the luminous layer 910.
The addressing method to address each electrooptical element by a pixel circuit provided for each of the plural electrooptical elements is referred to as “an active matrix addressing method,” and is disclosed in WO 98/3640.